I have 3 to 4 times a day server crash and I don't know why this is happening.
I have oxide install (latest version): Oxide.Rust Version: 2.0.4487

Of mods I have:
1. AdminRadar
2. AdvertMessages
3. EnhancedBanSystem.cs
4. ExtendedRecycler.cs
5. GatherManager.cs
6. GroupLimits.cs
7. MagicClockPanel.cs
8. MagicPanel.cs
9. NoGiveNotices.cs
10. NoGreen.cs
11. StackSizeController.cs
12. Vanish.cs
13. ZoneManager.cs

What exactly is "crashing" about it?

The server restarts

That isn't necessarily a crash. Some hosts have automated restarts when resource usage is too high, so you would need to do some digging to see what the actual cause is, whether it be from running out of memory, a host enforcing a limit, a scheduled restart with the host, or from an actual crash.

Thank You Wolf for info.